Commit b84d2b27 authored by Mark Brown's avatar Mark Brown Committed by Catalin Marinas
Browse files

kselftest/arm64: Test FPSIMD format data writes via NT_ARM_SVE in fp-ptrace 



The NT_ARM_SVE register set supports two data formats, the native SVE one
and an alternative format where we embed a copy of user_fpsimd_data as used
for NT_PRFPREG in the SVE register set. The register data is set as for a
write to NT_PRFPREG and changes in vector length and streaming mode are
handled as for any NT_ARM_SVE write. This has not previously been tested by
fp-ptrace, add coverage of it.

We do not support writes in FPSIMD format for NT_ARM_SSVE so we skip the
test for anything that would leave us in streaming mode.

Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20250718-arm64-fp-ptrace-sve-fpsimd-v1-1-7ecda32aa297@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent b5cebb5d

tools/testing/selftests/arm64/fp/fp-ptrace.c

+64 −2
Original line number Diff line number Diff line
@@ -1066,6 +1066,23 @@ static bool sve_write_supported(struct test_config *config) 
	return true;

}



static bool sve_write_fpsimd_supported(struct test_config *config)

{

	if (!sve_supported())

		return false;



	if ((config->svcr_in & SVCR_ZA) != (config->svcr_expected & SVCR_ZA))

		return false;



	if (config->svcr_expected & SVCR_SM)

		return false;



	if (config->sme_vl_in != config->sme_vl_expected)

		return false;



	return true;

}



static void fpsimd_write_expected(struct test_config *config)

{

	int vl;
@@ -1152,7 +1169,7 @@ static void sve_write_expected(struct test_config *config) 
	}

}



static void sve_write(pid_t child, struct test_config *config)

static void sve_write_sve(pid_t child, struct test_config *config)

{

	struct user_sve_header *sve;

	struct iovec iov;
@@ -1195,6 +1212,45 @@ static void sve_write(pid_t child, struct test_config *config) 
	free(iov.iov_base);

}



static void sve_write_fpsimd(pid_t child, struct test_config *config)

{

	struct user_sve_header *sve;

	struct user_fpsimd_state *fpsimd;

	struct iovec iov;

	int ret, vl, vq;



	vl = vl_expected(config);

	vq = __sve_vq_from_vl(vl);



	if (!vl)

		return;



	iov.iov_len = SVE_PT_SVE_OFFSET + SVE_PT_SVE_SIZE(vq,

							  SVE_PT_REGS_FPSIMD);

	iov.iov_base = malloc(iov.iov_len);

	if (!iov.iov_base) {

		ksft_print_msg("Failed allocating %lu byte SVE write buffer\n",

			       iov.iov_len);

		return;

	}

	memset(iov.iov_base, 0, iov.iov_len);



	sve = iov.iov_base;

	sve->size = iov.iov_len;

	sve->flags = SVE_PT_REGS_FPSIMD;

	sve->vl = vl;



	fpsimd = iov.iov_base + SVE_PT_REGS_OFFSET;

	memcpy(&fpsimd->vregs, v_expected, sizeof(v_expected));



	ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_SVE, &iov);

	if (ret != 0)

		ksft_print_msg("Failed to write SVE: %s (%d)\n",

			       strerror(errno), errno);



	free(iov.iov_base);

}



static bool za_write_supported(struct test_config *config)

{

	if ((config->svcr_in & SVCR_SM) != (config->svcr_expected & SVCR_SM))
@@ -1386,7 +1442,13 @@ static struct test_definition sve_test_defs[] = { 
		.name = "SVE write",

		.supported = sve_write_supported,

		.set_expected_values = sve_write_expected,

		.modify_values = sve_write,

		.modify_values = sve_write_sve,

	},

	{

		.name = "SVE write FPSIMD format",

		.supported = sve_write_fpsimd_supported,

		.set_expected_values = fpsimd_write_expected,

		.modify_values = sve_write_fpsimd,

	},

};